temple sealing info is incorrect on member record

I have a member of our ward who adopted their grandson as a "son". They recently went to the temple and sealed their "son" to them. I received the changed record for the "son", recording the temple sealing, but the change showed the sealing to his biological parents rather that to the adoptive grandparents. How do I correct this?

It is possible that the adoption was not recorded in the adoptive parents' records prior to the sealing and the temple only had the birth parents on record. Check the adoptive parents' records to see if the adopted son is on their records. Then contact the temple where the sealing was performed to see what needs to be done to correct the error.

IIRC, the membership record only has a checkmark for "Sealed to parents".

The membership system can only track one set of parents. If they've legally adopted their grandson, then you need to change the membership record to reflect that. In this case I'd change the son - that should update the parent's and grand parent's records.